Shouldn't distant objects appear magnified?

This educational paper [0] titled &quot;Expanding Confusion&quot; (2003) is a classic on the general topic and well worth the read.<p>Holding the two concepts of an accelerated (!) (in terms of objects [1]) expanding universe and the fixed finite speed of light simultaneously in one&#x27;s Euclidean head can be dizzying, so be prepare to draw and enjoy the hard earned manual labor of counterintuitive conclusions.<p>[0]<a href="https:&#x2F;&#x2F;arxiv.org&#x2F;pdf&#x2F;astro-ph&#x2F;0310808.pdf" rel="nofollow noreferrer">https:&#x2F;&#x2F;arxiv.org&#x2F;pdf&#x2F;astro-ph&#x2F;0310808.pdf</a><p>[1]<a href="https:&#x2F;&#x2F;bigthink.com&#x2F;starts-with-a-bang&#x2F;universe-expansion-not-accelerating&#x2F;" rel="nofollow noreferrer">https:&#x2F;&#x2F;bigthink.com&#x2F;starts-with-a-bang&#x2F;universe-expansion-n...</a>

Makes me think of this : <a href="https:&#x2F;&#x2F;en.m.wikipedia.org&#x2F;wiki&#x2F;Terrell_rotation" rel="nofollow noreferrer">https:&#x2F;&#x2F;en.m.wikipedia.org&#x2F;wiki&#x2F;Terrell_rotation</a><p>How when going at relativistic speeds, you start to appear to rotate to obervers even if you are going straight - you can even see behind the object!

Is it reasonable to view the Cosmic Microwave Background Radiation as being the limit of this? The remains of the big bang, maximally scaled up and red shifted as far as things can be today?

Love this, there are a few topics you hear about in class and you don&#x27;t realise how mind boggling they are until someone less says hold up...<p>The interpretation of the Poynting vector is another.

I&#x27;ve heard of &quot;adjusting for inflation&quot; but this is ridiculous!

Take this a further step. Assuming we had telescopes big enough and sensors sensitive enough, what does the structure of the deepest parts of space look like? Are there pre-galaxy-formation structures which are smaller than galaxies and yet take up huge swaths of sky? Are there structures from some point in the past that take up so much space on the sky that not very many of them can &quot;fit&quot;, and, if so, do the calculations work out so that an equivalent explanation for having not very many of them is that the [region of the] universe [which is observable to us] was just that much smaller back then?

Fascinating. A related question: When we look at Andromeda, which has a diameter of 220,000 light years, we are looking at it slightly edge on. Shouldn&#x27;t the stars on the back edge be in a relatively different place in the sky than the stars on the front edge since the galaxy has moved relative to us over that 220K light years?

One thing that always bothers me is time dilation when it comes to observing distant objects like this. If it takes 4 light years for the light to travel one way (and the one way speed of light still hasn&#x27;t been measured!), that is for the observer at the origin, the photons we observe, for them it is much less than 4 years, is it even in years? So if I look at alpha centauri with a telescope, it isn&#x27;t really aloha centauri 4 years ago that I am observing right? It&#x27;s much more recent than that?<p>Otherwise, if a 30yo person travels at the speed of light from alpha centauri to earth, when the person arrives will they be a 31yo(~) person who arrived 4 year later, effectively time traveling to the future? And if they return right away, will folks at alpha centauri meet a 32yo(~) person who came back 8 years later? If so, then maybe superman had the right idea about flying really fast around earth to travel in time, just not to the past.<p>Perhaps some billionaire will decide to spin around the solar system really fast for a few decades and skip a century or so? Haha!

Huh. That would make such objects even harder to detect, since the light is spread out over a larger area, so the amount of light hitting each pixel of the detector is less than if it wasn&#x27;t magnified.<p>On the other hand, it means you can see details you might not be able to otherwise.

This is kind of mind blowing to me. The linked xkcd is a fantastic (if exaggerated?) illustration of this effect.<p>Objects in mirror may be further then they appear.

Speaking of the expansion of the universe, in a very distant future when the expansion speed is so high that most of the galaxies won&#x27;t be visible from earth, their astronomers will be thinking the whole universe contains only a few galaxies. But wait, what if the universe we observe today also misses some parts that can&#x27;t be observed anymore?<p>Neil deGrasse Tyson explained it more clearly: <a href="https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?t=436&amp;v=TgA2y-Bgi3c">https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?t=436&amp;v=TgA2y-Bgi3c</a><p>That&#x27;s probably why it&#x27;s called the <i>observable</i> universe.

And based on the size of the magnification of the galaxies throughout time, we can tell whether the universe is expanding at a constant rate or accelerated or decelerated at certain point.

man that&#x27;s fucked up. i dont want to look at the sky anymore.

This XKCD strip would be genius if he used actual different historical cell phones - for awhile they were getting smaller, and then they started to get larger again!<p><a href="https:&#x2F;&#x2F;xkcd.com&#x2F;2622&#x2F;" rel="nofollow noreferrer">https:&#x2F;&#x2F;xkcd.com&#x2F;2622&#x2F;</a>

Is there an xkcd for _everything_?!?

&quot;Give us one free miracle and we can explain anything!&quot; - Terrance McKenna on modern science.